Field
The presently disclosed subject matter relates to intraluminal catheters for use in percutaneous transluminal coronary angioplasty (PTCA) or stent delivery systems or the like. Particularly, the disclosed subject matter relates to a catheter and system having an improved distal tip.
Description of Related Art
Intraluminal catheters are well known and beneficial for a variety of medical uses, including diagnostics, therapeutics, and treatment. For example, and not limitation, balloon catheters can be used for a number of different vascular and/or coronary applications. In percutaneous transluminal coronary angioplasty (PTCA) procedures, a guidewire is typically advanced into the coronary artery until the distal end of the guidewire crosses a lesion to be dilated. A dilatation catheter having an inflatable balloon on the distal portion thereof is advanced into the coronary anatomy over the guidewire until the balloon of the dilatation catheter is properly positioned across the lesion. Once properly positioned, the dilatation balloon is inflated with inflation fluid one or more times to a predetermined size to open up the vascular passageway. Generally, the inflated diameter of the balloon is approximately the same diameter as the native diameter of the body lumen being dilated so as to complete the dilatation, but not over-expand the artery wall. After the balloon is finally deflated, blood flow resumes through the dilated artery and the dilatation catheter and the guidewire can be removed therefrom.
In addition to or as an alternative of angioplasty procedures, it can be desirable to implant an intravascular prosthesis, generally called a stent, inside the artery at the site of the lesion. Stents can also be used to repair vessels having an intimal flap or dissection or to generally strengthen a weakened section of a vessel or to maintain its patency. Stents can be delivered to a desired location within a coronary artery in a contracted condition on a balloon of a catheter, which is similar or identical in many respects to a balloon angioplasty catheter. The balloon, and thus the stent, is expanded within the patient's artery to a larger diameter. The balloon is deflated to remove the catheter with the stent implanted at the site of the dilated lesion. See for example, U.S. Pat. No. 5,507,768 (Lau et al.) and U.S. Pat. No. 5,458,615 (Klemm et al.), each of which is hereby incorporated by reference in its entirety. Alternatively, the stent can be delivered to a desired location within a coronary artery in a contracted condition under a retractable sheath of a catheter, which when pulled back allows the stent to expand within the patient's artery to a larger diameter. See for example, U.S. Pat. Nos. 5,360,401, 7,850,724, and 8,257,420 and U.S. Patent Publication Nos. 2013/0304179, 2013/0304181, and 2012/0065644, each of which is hereby incorporated by reference in its entirety.
It is desirable to provide an intraluminal catheter with a soft tip having a small entry profile to provide trackability and flexibility and to prevent or minimize injury to a vessel during advancement within the tortuous anatomy of a patient's vascular. One challenge has been forming a tip with a reduced diameter and/or thickness. For example, the tip should be thin and flexible, yet needs to be sufficiently strong to prevent guidewire lumen collapse. Accordingly, there remains a need to provide a catheter tip having a reduced diameter and/or thickness and having improved performance.